Total study population N = 264
CI Controls
No. of children 74 190
Age during first wave
Mean in months (SD) * 39.8 (12.7) 45.6 (13.9)
Range in months 18–61 18–66
Gender
Male (%) 47 (63.5) 97 (51.1)
Female (%) 27 (36.5) 93 (48.9)
Socioeconomic status† (SD) 4.4 (1.3) 4.7 (1.0)
Language Skills
CDI–Language Comprehension (SD) ** 30.0 (13.3) 40.4 (11.8)
CDI–Expressive Language (SD) ** 31.2 (13.0) 43.1 (11.2)
RDLS–Receptive Language (SD) 84.8 (17.5)
SELT–Expressive Language (SD) 82.7 (14.6)
Preferred mode of communication
Oral language only (%) 27 (36.5)
Sign-supported Dutch (%) 40 (54.1)
Sign language only (%) 7 (9.5)
Age at first hearing aid acquisition, in months (SD) 6.9 (6.7) Age at implantation
Mean in months (SD) 16.8 (7.2)
Range in months 6–35
Duration of CI use
Mean in months (SD) 22.6 (12.0)
Range in months 2–45
Bilateral CI (%) 34 (46)
Simultaneous implantation (%) 25 (73.5)
Age at implantation, in months (range) 13 (6–24)
Sequential implantation (%) 9 (26.5)
Age at first implantation, in months (range) 18 (10–25) Age at second implantation, in months (range) 41 (20–69)
†The highest level of education of each parent and their net household income were categorized on a scale ranging from zero to five. Socioeconomic status (SES) was calculated by averaging these three scores.
Abbreviations: CDI, Child Development Inventory; RDLS, Reynell Developmental Language Scales; SELT, Schlichting Expressive Language Test; CI, cochlear implant; SD, standard deviation
* p < 0.01, ** p < 0.001
